The present invention relates to a power transmission apparatus used chiefly in a motorized two-wheeled vehicle such as a motorcycle or the like, for transmitting an output of an internal combustion engine to the wheel.
It has previously been proposed that in an apparatus of this kind, a crankshaft of an internal combustion engine, an intermediate driving shaft to be driven by the same, and input and output shafts of a gear transmission to be driven by the driving shaft are so arranged within a surrounding machine casing as to be in parallel rows one to another. In this case there has been an attempt to make an assembling work thereof simple and easy.
Further, it has been usual hitherto with this kind of apparatus that a starter means and an electric generator means which are comparatively large in weight were both provided only on one side of a longitudinal center line of the machine casing. This conventional one-sided arrangement causes the apparatus to become heavier on one side thereof, so that when the apparatus is mounted on a body of a motorized two-wheeled vehicle such as a motorcycle or the like, it is very difficult for the center of gravity of the vehicle be positioned on a center line connecting between the front wheel and the rear one of the vehicle, and for fulfilling this requirement, the apparatus has to be mounted thereon in such a condition that the same is biased on one side.